Wireless telecommunications systems transmit signals between users using radio frequency (RF) signals. A typical wireless system includes a plurality of base stations that are connected to the public switched telephone network (PSTN) via a mobile switching center (MSC). Each base station includes a number of radio transceivers that are typically associated with a transmission tower. Each base station is located so as to cover a geographic region known colloquially as a “cell.” Each base station communicates with wireless terminals, e.g. cellular telephones, pagers, and other wireless units, located in its geographic region or cell.
A base station includes a number of modules that process RF signals for communication with wireless terminals, e.g., cellular telephones, pagers. The modules of a typical base station include, by way of example, mixers, amplifiers, filters, transmission lines, antennas and other appropriate circuits. Each module of the base station is designed to allow the base station to communicate with wireless terminals in one of a number of possible frequency bands based on the service supported by the base station.
A variety of wireless services are offered throughout the world. For each service, a specific band or bands of the frequency spectrum is licensed for providing the service. For example, in the United States, cellular telephone service is typically available in the 824-849 Megahertz (MHz) and 869-894 MHz frequency bands and personal communication services (PCS) are offered in the 1850-1990 MHz frequency range. Conventionally, each service that is offered uses its own set of base stations. This is due in part to the fact that signals of the various services have different ranges due to differences in the frequencies of the signals being transmitted. Unfortunately, this does not allow a service provider to adequately leverage off existing infrastructure used for a first service when introducing a second service in a different frequency band in the same service area.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for improvements in implementing services in a single geographic area that use different portions of the frequency spectrum.